HIP 41378 e
HIP 41378 e
confirmed planet • updated: 2019-06-03
HIP 41378 e orbits the star HIP 41378, which is slightly larger and hotter than our Sun. Scientists found it using data from the K2 space telescope, which watches for tiny dips in starlight caused by planets passing in front.
This page summarizes a catalog entry. If a measurement is missing, it is not shown or guessed. Some values can differ slightly between studies; when that happens, we describe the range rather than picking a favorite without evidence.
Scientific context
Scientific context: This profile layers interpretation on top of archival measurements. Modeled bands appear where direct detections (like spectra or transits) are not listed.
What we can’t claim: surface conditions, biology, or breathable atmosphere without direct spectra.
This planet orbits its star every 131 days and is about 5.5 times wider than Earth. Because it was found by the transit method, we know its size but not its mass — so we can’t say how dense or heavy it is. Its orbit is likely circular, but that has not been measured directly.
Glossary (plain English)
- AU: the average Earth–Sun distance.
- Semi-major axis: the planet’s average distance from its star.
- Eccentricity: how oval the orbit is (0 = circle).
- Radial velocity: finding a planet by measuring a star’s tiny “wobble.”
- m·sin i: a minimum mass estimate; the true mass can be higher if the orbit is tilted.
- Equilibrium temperature: a rough estimate from starlight alone, not a surface reading.
HIP 41378 e was first reported in 2016 using the Transit method. The discovery is linked to observations from K2.
In transit work, astronomers watch for tiny, repeating dips in a star’s light as the planet passes in front of it. Follow-up observations help rule out false positives and refine the orbit.
This entry does not include a full orbital solution (period and semi‑major axis are not listed in the row).
Eccentricity is not provided here; many catalogs omit it when the solution is underconstrained. Because this is a multi‑planet system, stability is ultimately tested with dynamical (N‑body) fits; catalogs can update as models improve.
A measured mass is not available in this row, which limits what we can infer about composition.
Radius is not listed, so density and surface gravity cannot be derived from this row alone.
Why “m·sin i” shows up on RV planets
HIP 41378 e orbits HIP 41378.
A temperature near 6226 K places it on the hotter side of the main sequence. The system is about 346.7 light‑years away.
Several key parameters are not present in this single catalog row. Missing fields don’t mean the science is unknown—only that this particular snapshot doesn’t carry the values.
In this case the most noticeable gaps are: radius, catalog equilibrium temperature, orbital period, semi‑major axis, eccentricity, mass. As new observations arrive, archives often refresh these entries (and sometimes revise earlier numbers).
Scientists keep revisiting systems like this because each new instrument pass can tighten uncertainties: better timing improves the orbit, better spectra improves the star, and better follow‑up can confirm or refute competing solutions. Even when a planet is well‑established, refined stellar properties can shift the inferred planet size, temperature, and habitability context. Transit systems are especially valuable because they can be re‑observed for decades to detect subtle changes in timing or additional planets.